18991760 has 40 divisors (see below), whose sum is σ = 45104256. Its totient is φ = 7433600.

The previous prime is 18991757. The next prime is 18991769. The reversal of 18991760 is 6719981.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (18991769) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1235 + ... + 6285.

Almost surely, 2^18991760 is an apocalyptic number.

18991760 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18991760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22552128).

18991760 is an abundant number, since it is smaller than the sum of its proper divisors (26112496).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18991760 is a wasteful number, since it uses less digits than its factorization.

18991760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5111 (or 5105 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 41.

The square root of 18991760 is about 4357.9536482161. The cubic root of 18991760 is about 266.8015845057.

The spelling of 18991760 in words is "eighteen million, nine hundred ninety-one thousand, seven hundred sixty".